Did Neutrinos Really Break Light Speed?

Last week, scientists at the Gran Sasso National Laboratory in Italy claimed to observe neutrinos travelling faster than the speed of light. Now teams are preparing to test the claim.

28 September, 2011

What's the Latest Development?

Last week, a team of scientists at the Gran Sasso National Laboratory in Italy claimed to have observed neutrinos, subatomic particles that have a small but non-zero mass, travelling faster than the speed of light. "Physicists, for the most part, suspect that an unknown systematic error lies behind [the team's] startling result. But nothing obvious has emerged, and many see the experiment as a tour de force because of its high precision." In March 2011, the team at Gran Sasso observed neutrinos arriving to a fixed point faster than light would have. After testing the results for six month, they went public.

What's the Big Idea?

If the researchers' claim is correct, it would invalidate Albert Einstein's principle that matter cannot achieve light speed, upending one of the most accepted premises of modern physics. But not everyone at the Italian lab agreed to sign their name to the experiment's results. Physicist Caren Hagner declined to confirm the results her team had recorded because she wanted more time to validate the startling conclusion. Teams of physicists around the world are currently calibrating their own particle accelerators to test Gran Sasso's results.